The field of the invention relates generally to power systems and, more particularly, to a load apparatus that may be used in power systems.
At least some known systems, such as power systems, use at least one machine that is coupled to a load. The machine may be a turbine engine that generates mechanical rotational energy. The load may be an electrical system, such as an electrical generator or inverter, which converts the mechanical energy to electrical energy for a power output. The load may also be coupled to an energy storage device such that some of the power output may be stored for later use. For example, at least some known power systems provide bi-directional electrical energy or power flow, wherein the power output from the load may be transferred to the turbine engine to power the turbine engine or the power output may be delivered to, for example, the energy storage device for storage.
Some power systems that provide bi-directional power flow may use high speed generators to facilitate an increased power density. At least some known high speed generators are directly coupled to the turbine engine. More specifically, a rotating element, such as a drive shaft, of the turbine engine is directly coupled with a rotor shaft of the generator. The drive shaft rotates to enable the turbine engine to generate mechanical rotational energy. As the drive shaft rotates, the generator rotor shaft rotates and the generator is able to convert the mechanical energy to electrical energy.
Because there is no rotordynamic isolation between the high speed generator and the turbine engine, the drive shaft of the turbine engine may impact the rotor shaft of the high speed generator, or vice versa. For example, the high rotational speeds that are implemented may apply centrifugal forces on the drive shaft and/or the rotor shaft that may cause misalignment of the rotor shaft and/or the generator with respect to the drive shaft and/or the turbine engine. Such misalignment may lead to a failure of at least one component of the power system, prevent proper bi-directional power flow, and/or adversely affect the overall operation of the power system.
Accordingly, there is a need for a load that is able to facilitate bi-directional power flow, and wherein the load is rotordynamically isolated from the machine that it is coupled to.